Hi all,

I'm very new to STL, although I have experience in ladder programing. But, now I have to program in STL, and I check the help from Siemens here and there, also the manual about the STL and so on..

But I can't understand everything. For ex:

L     2#100000000
T     MW    30

or

L     L#16777216
T     %DB10.DBD4

What this even means?

Or where can I find some examples about STL?

Thanks in advance guys,

Hi

The PLC has two accumlators.
Instruction L is Load Accumulator 1:
1. ACC1 is copied into ACC2
2. ACC1 is loaded with specified data

Instruction T transfers ACC1 into a specified addtess.

Any Arithmetic instruction makes operation on ACC1 and ACC2
(or ACC1 in case of 1 argument operations like ABS, RND, NEGR, etc.)
and stores result in ACC1:

L #A // Load A into ACC1
L #B // Load B into ACC1 [now A is in ACC2]
/R   // ACC1:=A/B; interpreted as REAL [/I: Integer; /D: Double Integer]
T #C // Transfer Result to C

 Another Example:

STAGE           ACC1                  ACC2
BEFORE          DATA1                 DATA2
L L#12345       L#12345               DATA1   // ACC1-->ACC2; L#12345-->ACC1
L L#54321       L#54321               L#12345 // ACC1-->ACC2; L#54321-->ACC1
+D              L#66666               L#12345 // ACC1:=ACC2+ACC1; ACC2 not modified
T #Variable     L#66666               L#12345 // Variable:=ACC1;

L     2#100000000 // Load Binary Constant [2#] into ACC1
T     MW    30 // Transfer it into memory word 30

or

L     L#16777216 // Load Long [DInt] constant into ACC1
T     %DB10.DBD4 // Transfer it into DB10.DBD4

SYNTAX of CONSTANTS

xxxxx                    - 16-bit Integer Constant [-32767 .. 32767], i.e. 12345
L#xxxxx               - 32-bit Integer Constant i.e. L#12345
T#xxxxxms         - Time Constant [32-bit integer in ms], i.e. T#150ms
xxxxxx.x               - Real Constant

Address Length Specification:
M - Memory; L - Local Temp Variables; DB - Data Block.
Second Letter: B - Byte [8bits], W - Word [16Bits], D - Double Word [32-bits]

hi drozerce,

Top expanation Piotr.M

To say it easy:

drozerce

L     2#100000000
T     MW    30

or

L     L#16777216
T     %DB10.DBD4

What this even means?

 These are just Move- or Copy-commands.

 hope this helps,

regards,

Ok, thanks guys...but my question was not about L and T. I know what L and T means.

My problem was with the numbers

2#10000000 and L#16777216? How can I convert these into dec numbers?

OK, for 2#10000000 is 256 decimal, right? (the conversion I did it with PC Calculator Bin-->Dec)

but L#16777216?

Also, I have another issue:

(I will put my understanding in comment)

L    Db100.DBW308     // Load DB100.DBW308, which in my case is number, 400 
L     8                            // Load number 8
*I                                  // Multiply 400*8
LAR1                           // Load Adress register 1. But what this means? Is it doing something with 400*8, or what?
OPN   DB101              // Open DB 101

L     DBW [AR1,P#0.0]      // Load DB101.DBW0 ??? This is not very clear for me also, because it should not be DBW0.0, but it should be DBW400      
T     Db100.DBW300        // Transfer to DB100.DBW300

In this case I'm confused with the LAR1 step. I dont understand what it is doing.

Thanks again guys,

As someone wrote 

L#xxxxx               - 32-bit Integer Constant i.e. L#12345

So your L#16777216 

means 16777216 dec

Oh and 2#10000000 is 128 

Woops, you're right - I've counted 7 zeros, not 8 :p

Hi

Ref Numbers:

2# means constant is binary (you can convert it to decimal with calculator)

w#16#xxxx means constant is 16-bit Hex

dw#16#xxxxxxxx means constant is 32-bit Hex

L#xxx means constant is 32-bit integer and is given in decimal (L#16777216 = 16777216)

T#xxxms means constant is TIME [internally 32-bit integer in ms i.e. 1000 = 1second]

xxx.yyy means constant is REAL (you must give .xxx, for example 123 is integer, 123.0 is REAL)

L     8                            // Load number 8
*I                                  // Multiply 400*8 // This is to cinvert DBW308 to pointer format
                                        which will point to address 400 in the DB
LAR1                           // Put 400*8 into Address register 1.
OPN   DB101              // Open DB 101

L     DBW [AR1,P#0.0]      // Loads Word from data block which address is pointed by AR1 with
offset P#0.0 (see below). In Your case this will load L DBW400
T     Db100.DBW300        // Transfer to DB100.DBW300

// IMPORTANT NOTE: WHEN YOU QUALIFY DBXXX.YYY INSTRUCTION IMPLICITLY OPENS

// NEW DATA BLOCK. FOR NEXT TRANSFER YOU NEED REPEAT OPN DB101 INSTRUCTION!

// EXAMPLE

LAR1                           // Put 400*8 into Address register 1.
OPN   DB101              // Open DB 101

L     DBW [AR1,P#0.0]      // Loads Word from data block which address is pointed by AR1 with
offset P#0.0 (see below). In Your case this will load L DBW400
T     Db100.DBW300        // Transfer to DB100.DBW300

OPN   DB101              // Open DB 101

L     DBW [AR1,P#2.0]      // Loads Word from data block which address is pointed by AR1 with
offset P#2.0 (see below). In Your case this will load L DBW402
T     Db100.DBW302        // Transfer to DB100.DBW302

In a nutshell:

to construct pointer to BIT x.y (for example to DBX12.4)

Pointer:=x*8+y;

to construct pointer to a whole address xxx:

Pointer:=xxx*8

then move pointer into address register by using instruction LAR1

L DB?[AR1,P#x.y] loads data (?: B = BYTE, W = WORD, D = 32-BIT Word) from address

specified in AR1 increased by x.y. for example

you have a structure which begins from address NNNN and want to query a bit which is

stored in this structure in 10.5 you query it  A DBX[AR1,P#10.5]

Let's assume NNNN is 100 - we load AR1 with 100*8=800

and do A DBX[AR1,P#10,5] - it will query bit DBX810.5

this way you can examine structures in loops or when address is calculated i.e.

when you handle recipes, etc.

Thanks again guys,

Thanks Piotr for the explanation,

and for your patience...Very helpfull!